1. Field of the Invention
The present invention relates a dental splint for stabilizing mobile or unstable human or animal teeth or firmly rooted teeth and more, particularly an apparatus and method for fabricating such a splint and the procedure for installing same.
2. Description of the Related Art
Stabilizing dental retainers and/or dental splints have been used in dentistry and orthodontics for many years to maintain natural teeth in a desired position. For example, it often is necessary to immobilize (and/or support) teeth which have been re-positioned orthodontically (especially when that orthodontic treatment has resulted in a condition called “root blunting” or “root resorption”), or teeth which exhibit a loss of bone support as result of periodontal disease. Stabilization also may be indicated in circumstances resulting from traumatic injury. As a general proposition, stabilization of teeth through use of a dental splint often involves connecting the teeth to be supported to one or more teeth that are firmly anchored in the mouth.
Historically, a number of different removable facial and lingual devices have been employed to stabilize teeth. The well-known Hawley Retainer is often employed with respect to maxillary and or mandibular anterior teeth. That type of retainer uses a metal wire positioned on the facial surface of teeth connected to an embeddable acrylic on the lingual aspect of the subject teeth to aid in retention of the appliance. Additional attempts have involved bonding various components to the lingual aspect on the anterior teeth and imbedding a metal wire within a bonded bracket or within the bonded material itself. The actual thickness of these bonded components frequently result in accessibility concerns for hygiene maintenance as well as plaque and calculus retention which can contribute to both periodontal as well as restorative concerns (i.e., cavities). Other approaches for the stabilization of teeth have employed a metal wire which is custom adapted to a groove or channel that has been cut into the enamel (or into the dentin) on the lingual aspect of the teeth. The wire is then fitted into the channel and overlaid with composite and bonded into place. Although this process reduces hygienic concerns, it involves removal of sound tooth structure and consequently is not reversible. Still other methods have involved the use of extracoronal dental splints fabricated from metal or other malleable strips of materials that are attached to the inner dental arch with composite or other bonding materials. Typical examples of removable facial and lingual devices found in the prior art are described below.
U.S. Pat. Appln. No. 2010/0104998 entitled “Dental Splint” and applied for by Farrell et al. discloses a “removable” occlusal dental splint for treatment of certain orofacial disorders and includes a chewing surface where the splint can be employed while eating. The specification describes the one or more clasps fitted to the splint for adjusting the fit of the splint and to help retain the appliance in the mouth.
U.S. Pat. No. 4,412,818 entitled “Method for Splinting Animal Teeth,” and issued to Thomson discloses a simple method of stabilizing grazing animal's teeth (all of them) where an aperture brace (single elongated strip) is bonded to the teeth by means of a bonding composition leaving the incisal edges of the teeth exposed.
U.S. Pat. No. 4,735,571 entitled “Dental Splint” and issued to Salvo discloses a dental splint procedure comprising the steps of providing a rigid bar member; forming a dental preparation in the surface (only so deep as into the dentin) of a plurality of teeth providing a filled resin composite material and bonding agent to adhere the bar; coating the walls and floor of the bar; coating the floor and walls of the dental preparation; mounting the bar into the preparation; and covering the bar and preparation so as to form a unitary structure.
U.S. Pat No. 4,433,960, entitled “Extracoronal Dental Splint and Splinting Method,” issued to Garito discloses a dental splint and dental splint procedure which utilizes a thin, flat, slightly malleable perforated strip or mesh (grid-like material) which is adhered to the patient's inner dental arch employing a pressure-sensitive adhesive backing. Garito's dental splint is actually two strip segments with a hinge connecting together the two similar segments at their adjacent ends by way of a pin. Subsequently, the two strip segment is covered with a thin layer of resin or composite material, which when hardened firmly bonds the strip to the patient's teeth (i.e. to stabilizing any mobile teeth).
U.S. Pat No. 4,504,229 entitled “Dental Placement Device and Method,” issued to Garito et al discloses a dental placement device and related method for placement of dental splints for stabilizing mobile or avulsed teeth. In particular, the procedure includes the steps of (a) bonding a malleable mesh-type elongated strip onto and over the occlusial surface of the tooth; (b) trimming off excess strip sections extending beyond the occlusial surface; and (c) adjusting the exposed bonded strip to enhance its biting function. The dental placement procedure includes the steps of inserting monofilaments which are joined at opposite ends by common joining strips (interproximally into a segment of teeth); (b) placing splinting material across the teeth and in the interproximal spaces; (c) looping the monofilaments over the splinting material and back into the interproximal spaces and pulling same so as to draw the splinting material into the said interproximal spaces; and (d) applying a hardenable bonding material over the splinting material while temporarily held by the monofilaments and allowing the bonding material to harden. The monofilaments are also employed to draw splinting material into interproximal spaces during the procedure.
U.S. Pat. No. 4,384,854 entitled “Anterior Splint,” and issued to Garfinkel discloses an anterior splint including an elongated anchoring member (i.e., “tab”) and wire mesh strip coupled to the anchoring member wherein the wire mesh strip is engaged to the lingual surface of the teeth and forced into the interproximal spaces. In other words, Garfinkel's dental splint requires that the dentist pull labially on the tab which forces the wire mesh into the interproximal spaces against the lingual surfaces. Subsequently, the wire mesh and tabs are bonded to the teeth lingually and interproximally (with excess removed). An optional step is disclose of stripping a thin ledge on the anterior teeth (interproximally) to provide more facility in the inserting of tabs.
U.S. Pat. No. 6,916,178 entitled “Dental Splint and Splinting Method,” and issued to Lans discloses a splint and method for installing same on adjacent teeth. The splint is formed of a rigid sheet material (stainless steel or titanium 0.0007 inches thick) and has two support prongs extending in opposite direction to each other from two shoulders that are connected by an arch portion that extends between the shoulders. The method includes installing aligned grooves cut into adjacent teeth using a simple inverted core carbide bur. The grooves are partially filled with composite resin, after which the splint is embedded in the composite resin, which is then cured and finished to a smooth surface.
U.S. Pat. No. 7,048,542 entitled “Dental Splint,” and issued to Arx, discloses a dental splint for fixing a tooth with increased mobility. This splint has a plurality of eyes, wherein adjacent eyes interconnected via a flat connection and individual eyes, each have a through-opening which is surrounded by a link so that it is possible (by way of the through-opening) to apply an adhesive to the tooth located behind the respective through-opening to secure the dental splint on the tooth. Each eye is substantially diamond-shaped with a flat connection between the eye at least approximately twice as wide as the link which surrounds the through-openings.
U.S. Pat. No. 5,184,955 entitled “Device for Temporary Dental Splinting,” and issued to Baer et al. discloses a device and a related method for temporary fixation of teeth comprising a wire-shaped connecting link and a row of annular composite carriers wherein composite material is applied to each tooth surface. The invention further includes an embodiment where the annular composite carriers have two sides which lie substantially opposite of one another, including a hole for the connecting link. Moreover, the device can be enhanced through ergonomic principles such as a “skull-capped” configuration with openings to receive the wire-shaped connecting link.
U.S. Pat. No. 4,533,320 entitled “Stabilizing Retainer System” and issued to Piekarsky discloses a stabilizing retainer (and similar method of installing same) comprising a conformable wire for placement in a predetermined position and spanning a series of teeth; a plurality of bonding pads for securing the wire to a group of teeth; wherein each said bonding pad further includes a basal surface portion and transverse channel for receiving the wire and securing it to each pad.
U.S. Pat. No. 5,087,202 entitled “Device to Fix or Control the Mutual Position of Teeth,” and issued to Krenkel discloses a device to fix and control the mutual position of teeth including a unitary strip of deformable material substantially elongated in a longitudinal direction. Each unitary strip includes a plurality of anchor elements which are connected to one another by a force transfer member (claimed as a “continuous connecting bar” or “connection bars”). The various embodiments of Krenkel each disclose anchor element being substantially ring-like in configuration and the rings exhibit chamfered inner.
U.S. Pat. Appln. No. 2006/0078849 entitled “Dental Splint” and applied for by Parks discloses a dental splint which involves the installation a plurality of splint posts onto one or more teeth and the insertioning/installation of a strip to interconnect the plurality of the splints. One embodiment discloses that each splint post has a ovoidal-shaped top and a rectangular base with each strip including similar ovoidal shaped slots for connecting the strip and the splint posts. Another similar embodiment includes a splint post with a ovoidal base and rectangular top where the base and top are separable (including a notches and slots for securing the two parts). Yet another embodiment provides an additional groove disposed in the top of the splint posts for receiving a wire or band. Similarly, another embodiment discloses a splint post which has the ability to move laterally (90°) within the slot relative to the longitudinal axis of the strip. Moreover, the strip has “snap into” channels for receiving “keys” provided on the bottom of the splint post top. Another embodiment of Parks discloses a domed top splint post which includes a flat base and a domed top. The flat base includes a peel strip that can be removed to expose resin for adhering to the teeth. The domed top includes a passage which includes one or more protrusions that engage one or more ridges on a strip to fasten the splint posts (i.e. zip or cable ties). Another similar embodiment disclosed by Parks utilizes a rectangular top splint post instead of a domed top. Yet another embodiment of Parks discloses silted (“snap” top) splint post which includes a slit to allow a strip to snap into a deeper and wider passage.
The prior art also discloses a method of fabricating dental devices. For example, U.S. Pat. No. 6,671,539 entitled “Method and Apparatus for Fabricating Orthognathic Surgical Splints,” and issued to Gateno discloses a method of forming a surgical splint to receive a patient's dentition allowing selective alignment of the upper and lower jaw relative to the patient's skull during surgery comprising the steps of: (a) generating a CT computer model of bone structure; (b) generating a digital dental computer model of patient's dentition; (c) positioning a plurality of markers relative to the patient's dentition in both the CT and digital computer models; (d) forming a composite model of the CT and digital dental model; (e) displaying the composite computer model; (f) forming a planned position computer model (repositioning of upper or lower jaw with respect to patient's skull); (g) forming a computer model surgical splint of patient's dentition; and (h) forming a surgical splint from the computer model surgical splint.
While such dental splints and methods described above offer some advantages over prior methods, they still have some disadvantages when compared to the present invention addressed herein. For example, those disadvantages include: (1) greater time and effort required for their fabrication and installation; (2) a less precise matching of the appliance to the contours of the existing teeth of the inner arch which contributes to hygienic and restorative concerns; (3) greater bulk than the dental splint invention addressed herein; (4) the use of materials that are not as dense, color stable and bio-compatible as those used in the present invention; (5) the need to apply extra composite or bonding material around the edges of the splint; (6) less aesthetically pleasing appearance due to the use of non-tooth-colored material; (7) the need to have the splint span a larger minimum number of teeth (e.g., four teeth) whereas the present invention can be utilized with a minimum of two teeth (i.e., one tooth to be supported attached to one support tooth); (8) the need to use acrylic monomer which may cause allergic reactions or irritations; and (9) the need for one or more stable or firmly-rooted teeth to which to bond the dental splint.
Having set forth the limitations of the prior art, it is clear that what is required is a custom-fabricated lingual extra-coronal dental splint along with the processes for manufacturing and bonding or installing that splint. One objective of the present invention is to produce an ideal splint that should exhibit the following characteristics: (1) it should be made of a tooth colored material, (2) it should be strong and rigid even when manufactured in thin dimensions, (3) it should maintain existing tooth contours without creating bulkiness, (4) it should enhance hygiene maintenance and thereby also decrease restorative concerns, (5) it ordinarily should not require the alteration of existing tooth structure, and (6) it could be removable by a dental professional if the conditions prompting its installation change (for example, in the case of a traumatic injury) or if the patient desires removal of the device.